Retirement and Postemployment Benefits (Plan Assets and Expected Cash Flows) (Details) - USD ($) $ in Millions		1 Months Ended	12 Months Ended
		Jan. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016		Dec. 31, 2015
Assumptions Used in Calculations (Numeric) [Abstract]
Number Of Days Notice Required To Redeem Shares			45 days
Pension Benefits United States [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		$ (3,243)	$ (3,227)	$ (4,462)	$ (3,243)		$ (3,227)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(3,243)	(3,227)	(4,462)
Balance at end of period			(3,243)	(3,227)
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions			79	158
Amount to be contributed to plan in the next fiscal year			$ 0
Expected amount of benefit payments in the next period for non-qualified plans					17
Estimated Future Benefit Payments (Details) [Abstract]
2017					251
2018					252
2019					261
2020					263
2021					267
2022-2026					1,344
Pension Benefits United States [Member] | Subsequent Event [Member]
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions		53
Pension Benefits United States [Member] | Master Trust [Member]
Assumptions Used in Calculations (Numeric) [Abstract]
The limited lives of four partnership of private equity investments (in years)			10 years
The limited lives of fifth partnership of private equity investments (in years)			15 years
The amount of potential liability that maybe required to be funded by the master trust during life of the partnership					$ 22
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					100.00%	[1]	100.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[1]		100.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(3,381)	$ (3,387)	(3,387)	$ (3,381)		$ (3,387)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(3,381)	(3,387)
Balance at end of period			(3,381)	(3,387)
Pension Benefits United States [Member] | Master Trust [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(714)	(889)	(889)	(714)		(889)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(714)	(889)
Balance at end of period			(714)	(889)
Pension Benefits United States [Member] | Master Trust [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(909)	(851)	(851)	(909)		(851)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(909)	(851)
Balance at end of period			(909)	(851)
Pension Benefits United States [Member] | Master Trust [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(40)	(42)	(54)	(40)		(42)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(40)	(42)	(54)
Actual return on plan assets relating to assets still held at the reporting date			1	2
Actual return on plan assets relating to assets sold during the period				(1)
Purchases, sales and settlements			(3)	(13)
Balance at end of period			(40)	(42)
Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					181		225
Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					181		225
Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					152		172
Measured at fair value using net asset value per share	[2]				272		197
Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					152		172
Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | International Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				551		454
Pension Benefits United States [Member] | Master Trust [Member] | Commingled Debt Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				546		514
Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					381		501
Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					381		492
Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		9
Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					850		747
Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					837		737
Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					13		10
Fair value at end of period		(13)	(10)	(21)	(13)		(10)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(13)	(10)	(21)
Actual return on plan assets relating to assets still held at the reporting date			0	0
Actual return on plan assets relating to assets sold during the period				(1)
Purchases, sales and settlements			3	(10)
Balance at end of period			(13)	(10)
Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					8		14
Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					8		14
Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Commodities Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				0		70
Pension Benefits United States [Member] | Master Trust [Member] | Real Estate Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				102		118
Pension Benefits United States [Member] | Master Trust [Member] | Private Equity Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				80		81
Pension Benefits United States [Member] | Master Trust [Member] | Hedge Fund Of Funds Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				167		171
Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					61		80
Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					61		80
Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					3		11
Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					3		11
Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					27		32
Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					27		32
Fair value at end of period		(27)	(32)	(33)	(27)		(32)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(27)	(32)	(33)
Actual return on plan assets relating to assets still held at the reporting date			1	2
Actual return on plan assets relating to assets sold during the period				0
Purchases, sales and settlements			(6)	(3)
Balance at end of period			(27)	(32)
Pension Benefits United States [Member] | Master Trust [Member] | Receivables And Payables Net [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	[3]	(15)	(49)	(49)	(15)		(49)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	[3]	(15)	(49)
Balance at end of period	[3]		(15)	(49)
Pension Benefits United States [Member] | Master Trust [Member] | Account 401 H [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(123)	(111)	(111)	(123)		(111)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(123)	(111)
Balance at end of period			(123)	(111)
Pension Benefits United States [Member] | Master Trust [Member] | Total Trust Assets Not Including 401 H Assets [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(3,243)	(3,227)	(3,227)	$ (3,243)		$ (3,227)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(3,243)	(3,227)
Balance at end of period			$ (3,243)	(3,227)
Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					52.00%	[1]	51.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[1]		50.00%
Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member] | Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					30.00%	[1]	25.00%
Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets	[4]				12.00%	[1]	13.00%
Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member] | Alternative Investments [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					10.00%	[1]	13.00%
Pension Benefits United States [Member] | Master Trust [Member] | Immunizing Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					46.00%	[1]	47.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[1]		48.00%
Pension Benefits United States [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets	[4]				43.00%	[1]	42.00%
Pension Benefits United States [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Derivatives [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					3.00%	[1]	5.00%
Pension Benefits United States [Member] | Master Trust [Member] | Liquidity Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					2.00%	[1]	2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[1]		2.00%
Pension Benefits United Kingdom [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					100.00%		100.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			100.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(7,211)	$ (7,625)	(7,734)	$ (7,211)		$ (7,625)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(7,211)	(7,625)	(7,734)
Balance at end of period			(7,211)	(7,625)
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions			330	366
Amount to be contributed to plan in the next fiscal year			$ 389
Recurrence of formal actuarial valuations (in years)			3 years
Percentage of deficit funding requirements permitted to recover in rates			78.00%
Estimated Future Benefit Payments (Details) [Abstract]
2017					314
2018					317
2019					322
2020					326
2021					329
2022-2026					1,693
Pension Benefits United Kingdom [Member] | Subsequent Event [Member]
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Amount to be contributed to plan in the next fiscal year		98
Pension Benefits United Kingdom [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(42)	$ (55)	(55)	(42)		(55)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(42)	(55)
Balance at end of period			(42)	(55)
Pension Benefits United Kingdom [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(2,942)	(3,009)	(3,009)	(2,942)		(3,009)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(2,942)	(3,009)
Balance at end of period			(2,942)	(3,009)
Pension Benefits United Kingdom [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		0	0	0	$ 0		$ 0
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		0	0
Balance at end of period			$ 0	0
Pension Benefits United Kingdom [Member] | Cash And Cash Equivalents [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					1.00%		1.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			1.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					$ 42		$ 55
Pension Benefits United Kingdom [Member] | Cash And Cash Equivalents [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					42		55
Pension Benefits United Kingdom [Member] | Cash And Cash Equivalents [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United Kingdom [Member] | Cash And Cash Equivalents [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					$ 0		$ 0
Pension Benefits United Kingdom [Member] | UK Companies Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					3.00%		3.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			3.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[5]				$ 210		$ 274
Pension Benefits United Kingdom [Member] | European Companies Excluding UK Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					2.00%		2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			2.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[5]				$ 177		$ 190
Pension Benefits United Kingdom [Member] | Asian Pacific Companies Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					2.00%		2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			2.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[5]				$ 140		$ 132
Pension Benefits United Kingdom [Member] | North American Companies Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					3.00%		3.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			3.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[5]				$ 227		$ 220
Pension Benefits United Kingdom [Member] | Emerging Markets Companies Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					3.00%		4.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			1.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[5]				$ 209		$ 284
Pension Benefits United Kingdom [Member] | Global Equities Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					6.00%		6.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			3.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[5]				$ 466		$ 500
Pension Benefits United Kingdom [Member] | Currency Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					0.00%		1.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			0.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[5]				$ 0		$ 39
Pension Benefits United Kingdom [Member] | Global Tactical Asset Allocation Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					33.00%		31.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			40.00%
Pension Benefits United Kingdom [Member] | Other Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[5]				$ 2,363		$ 2,384
Pension Benefits United Kingdom [Member] | UK Corporate Bonds Commingled Debt Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[5]				0		2
Pension Benefits United Kingdom [Member] | UK Gilts Commingled Debt Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[5]				$ 0		$ 3
Pension Benefits United Kingdom [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets	[6]				41.00%		40.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[6]		39.00%
Pension Benefits United Kingdom [Member] | United Kingdom Corporate Bonds Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					$ 2		$ 364
Pension Benefits United Kingdom [Member] | United Kingdom Corporate Bonds Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United Kingdom [Member] | United Kingdom Corporate Bonds Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					2		364
Pension Benefits United Kingdom [Member] | United Kingdom Corporate Bonds Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United Kingdom [Member] | United Kingdom Gilts Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					2,940		2,645
Pension Benefits United Kingdom [Member] | United Kingdom Gilts Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Pension Benefits United Kingdom [Member] | United Kingdom Gilts Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					2,940		2,645
Pension Benefits United Kingdom [Member] | United Kingdom Gilts Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					$ 0		$ 0
Pension Benefits United Kingdom [Member] | Alternative Investments [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					6.00%		7.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			6.00%
Pension Benefits United Kingdom [Member] | Real Estate Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share					$ 435		$ 533
Other Postretirement Benefits United States [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					100.00%		100.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			100.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(378)	$ (379)	(484)	$ (378)		$ (379)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(378)	(379)	(484)
Balance at end of period			(378)	(379)
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions			19	17
Amount to be contributed to plan in the next fiscal year			$ 14
Estimated Future Benefit Payments (Details) [Abstract]
2017					52
2018					51
2019					51
2020					50
2021					49
2022-2026					228
Expected Federal Subsidy (Details) [Abstract]
Federal subsidy 2017					1
Federal subsidy 2018					1
Federal subsidy 2019					1
Federal subsidy 2020					0
Federal subsidy 2021					0
Federal subsidy 2022-2026					$ 2
Other Postretirement Benefits United States [Member] | Cash And Cash Equivalents [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets	[7]				2.00%		2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[7]		5.00%
Other Postretirement Benefits United States [Member] | Money Market Funds [Member]
Assumptions Used in Calculations (Numeric) [Abstract]
Number of months from date of purchase that investment must mature			13 months
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(5)	$ (6)	(6)	$ (5)		$ (6)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(5)	(6)
Balance at end of period			$ (5)	(6)
Other Postretirement Benefits United States [Member] | Money Market Funds [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					5		6
Other Postretirement Benefits United States [Member] | Money Market Funds [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Other Postretirement Benefits United States [Member] | Money Market Funds [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					$ 0		$ 0
Other Postretirement Benefits United States [Member] | Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					48.00%		48.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			45.00%
Other Postretirement Benefits United States [Member] | United States Large Cap Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[8]				$ 123		$ 129
Other Postretirement Benefits United States [Member] | Commingled Debt Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[8]				$ 114		$ 109
Other Postretirement Benefits United States [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets	[9]				50.00%		50.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[9]		50.00%
Other Postretirement Benefits United States [Member] | Municipalities Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					$ 12		$ 23
Other Postretirement Benefits United States [Member] | Municipalities Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Other Postretirement Benefits United States [Member] | Municipalities Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					12		23
Other Postretirement Benefits United States [Member] | Municipalities Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Other Postretirement Benefits United States [Member] | Receivables And Payables Net [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	[10]	(1)	$ (1)	(1)	(1)		(1)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	[10]	(1)	(1)
Balance at end of period	[10]		(1)	(1)
Other Postretirement Benefits United States [Member] | Account 401 H [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(123)	(111)	(111)	(123)		(111)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(123)	(111)
Balance at end of period			(123)	(111)
Other Postretirement Benefits United States [Member] | Total Trust Assets Not Including 401 H Assets [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(254)	(267)	(267)	(254)		(267)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(254)	(267)
Balance at end of period			(254)	(267)
Other Postretirement Benefits United States [Member] | Total Trust Assets Not Including 401 H Assets [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(5)	(6)	(6)	(5)		(6)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(5)	(6)
Balance at end of period			(5)	(6)
Other Postretirement Benefits United States [Member] | Total Trust Assets Not Including 401 H Assets [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(12)	(23)	(23)	(12)		(23)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(12)	(23)
Balance at end of period			(12)	(23)
Other Postretirement Benefits United States [Member] | Total Trust Assets Not Including 401 H Assets [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		0	0	0	0		0
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		0	0
Balance at end of period			0	0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(1,315)	(1,289)	(1,301)	(1,315)		(1,289)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(1,315)	(1,289)	(1,301)
Balance at end of period			(1,315)	(1,289)
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions			66	$ 54
Amount to be contributed to plan in the next fiscal year			$ 0
Expected amount of benefit payments in the next period for non-qualified plans					4
Estimated Future Benefit Payments (Details) [Abstract]
2017					105
2018					108
2019					110
2020					111
2021					113
2022-2026					569
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Subsequent Event [Member]
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions		18
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member]
Information About Plan Assets (Numeric) [Abstract]
Value of plan U.S. pension trust assets that relate to PPL subsidiary					1,300		$ 1,300
Undivided interest percentage in each asset category that PPL subsidiary holds			41.00%	40.00%
Assumptions Used in Calculations (Numeric) [Abstract]
The limited lives of four partnership of private equity investments (in years)			10 years
The limited lives of fifth partnership of private equity investments (in years)			15 years
The amount of potential liability that maybe required to be funded by the master trust during life of the partnership					$ 22
Number Of Days Notice Required To Redeem Shares			45 days
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					100.00%		100.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			100.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(3,381)	$ (3,387)	$ (3,387)	$ (3,381)		$ (3,387)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(3,381)	(3,387)
Balance at end of period			(3,381)	(3,387)
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(714)	(889)	(889)	(714)		(889)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(714)	(889)
Balance at end of period			(714)	(889)
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(909)	(851)	(851)	(909)		(851)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(909)	(851)
Balance at end of period			(909)	(851)
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(40)	(42)	(54)	(40)		(42)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(40)	(42)	(54)
Actual return on plan assets relating to assets still held at the reporting date				2
Actual return on plan assets relating to assets sold during the period			0	(1)
Purchases, sales and settlements			(3)	(13)
Balance at end of period			(40)	(42)
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					181		225
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					181		225
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					152		172
Measured at fair value using net asset value per share	[2]				272		197
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					152		172
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | International Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				551		454
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Commingled Debt Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				546		514
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					381		501
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					381		492
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		9
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					850		747
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					837		737
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					13		10
Fair value at end of period				(21)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period				(21)
Actual return on plan assets relating to assets still held at the reporting date				0
Actual return on plan assets relating to assets sold during the period			0	(1)
Purchases, sales and settlements			3	(10)
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					8		14
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					8		14
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Commodities Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				0		70
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Real Estate Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				102		118
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Private Equity Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				80		81
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Hedge Fund Of Funds Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				167		171
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					61		80
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					61		80
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					3		11
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					3		11
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					27		32
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					27		32
Fair value at end of period				(33)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period				(33)
Actual return on plan assets relating to assets still held at the reporting date				2
Actual return on plan assets relating to assets sold during the period			1	0
Purchases, sales and settlements			(6)	(3)
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Receivables And Payables Net [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	[3]	(15)	(49)	(49)	(15)		(49)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	[3]	(15)	(49)
Balance at end of period	[3]		(15)	(49)
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Account 401 H [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(123)	(111)	(111)	(123)		(111)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(123)	(111)
Balance at end of period			(123)	(111)
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Total Trust Assets Not Including 401 H Assets [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(3,243)	(3,227)	(3,227)	$ (3,243)		$ (3,227)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(3,243)	(3,227)
Balance at end of period			$ (3,243)	(3,227)
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					52.00%	[1]	51.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[1]		50.00%
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member] | Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					30.00%	[1]	25.00%
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets	[4]				12.00%	[1]	13.00%
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member] | Alternative Investments [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					10.00%	[1]	13.00%
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Immunizing Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					46.00%	[1]	47.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[1]		48.00%
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets	[4]				43.00%	[1]	42.00%
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Derivatives [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					3.00%	[1]	5.00%
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Liquidity Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					2.00%	[1]	2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[1]		2.00%
LG And E And KU Energy LLC [Member] | Other Postretirement Benefits United States [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(98)	$ (88)	(82)	$ (98)		$ (88)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(98)	(88)	(82)
Balance at end of period			(98)	(88)
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions			20	17
Amount to be contributed to plan in the next fiscal year			14
Estimated Future Benefit Payments (Details) [Abstract]
2017					14
2018					14
2019					15
2020					16
2021					16
2022-2026					82
Expected Federal Subsidy (Details) [Abstract]
Federal subsidy 2017					0
Federal subsidy 2018					0
Federal subsidy 2019					1
Federal subsidy 2020					0
Federal subsidy 2021					0
Federal subsidy 2022-2026					2
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(318)	(297)	(301)	(318)		(297)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(318)	(297)	(301)
Balance at end of period			(318)	(297)
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions			35	$ 13
Amount to be contributed to plan in the next fiscal year			$ 0
Estimated Future Benefit Payments (Details) [Abstract]
2017					25
2018					25
2019					25
2020					25
2021					24
2022-2026					110
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member]
Information About Plan Assets (Numeric) [Abstract]
Value of plan U.S. pension trust assets that relate to PPL subsidiary					318		$ 297
Undivided interest percentage in each asset category that PPL subsidiary holds			10.00%	9.00%
Assumptions Used in Calculations (Numeric) [Abstract]
The limited lives of four partnership of private equity investments (in years)			10 years
The limited lives of fifth partnership of private equity investments (in years)			15 years
The amount of potential liability that maybe required to be funded by the master trust during life of the partnership					$ 22
Number Of Days Notice Required To Redeem Shares			45 days
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					100.00%		100.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average			100.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(3,381)	$ (3,387)	$ (3,387)	$ (3,381)		$ (3,387)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(3,381)	(3,387)
Balance at end of period			(3,381)	(3,387)
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(714)	(889)	(889)	(714)		(889)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(714)	(889)
Balance at end of period			(714)	(889)
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(909)	(851)	(851)	(909)		(851)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(909)	(851)
Balance at end of period			(909)	(851)
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(40)	(42)	(54)	(40)		(42)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(40)	(42)	(54)
Actual return on plan assets relating to assets still held at the reporting date				2
Actual return on plan assets relating to assets sold during the period			0	(1)
Purchases, sales and settlements			(3)	(13)
Balance at end of period			(40)	(42)
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					181		225
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					181		225
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					152		172
Measured at fair value using net asset value per share	[2]				272		197
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					152		172
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Equity Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | International Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				551		454
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Commingled Debt Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				546		514
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					381		501
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					381		492
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		9
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					850		747
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					837		737
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					13		10
Fair value at end of period				(21)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period				(21)
Actual return on plan assets relating to assets still held at the reporting date				0
Actual return on plan assets relating to assets sold during the period			0	(1)
Purchases, sales and settlements			3	(10)
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					8		14
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					8		14
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Commodities Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				0		70
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Real Estate Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				102		118
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Private Equity Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				80		81
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Hedge Fund Of Funds Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share	[2]				167		171
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					61		80
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					61		80
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					3		11
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					3		11
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					27		32
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					0		0
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share					27		32
Fair value at end of period				(33)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period				(33)
Actual return on plan assets relating to assets still held at the reporting date				2
Actual return on plan assets relating to assets sold during the period			1	0
Purchases, sales and settlements			(6)	(3)
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Receivables And Payables Net [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	[3]	(15)	(49)	(49)	(15)		(49)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	[3]	(15)	(49)
Balance at end of period	[3]		(15)	(49)
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Account 401 H [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(123)	(111)	(111)	(123)		(111)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		(123)	(111)
Balance at end of period			(123)	(111)
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Total Trust Assets Not Including 401 H Assets [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period		(3,243)	(3,227)	(3,227)	$ (3,243)		$ (3,227)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period		$ (3,243)	(3,227)
Balance at end of period			$ (3,243)	$ (3,227)
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					52.00%	[1]	51.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[1]		50.00%
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member] | Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					30.00%	[1]	25.00%
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets	[4]				12.00%	[1]	13.00%
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Growth Portfolio [Member] | Alternative Investments [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					10.00%	[1]	13.00%
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Immunizing Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					46.00%	[1]	47.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[1]		48.00%
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets	[4]				43.00%	[1]	42.00%
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Derivatives [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					3.00%	[1]	5.00%
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | Master Trust [Member] | Liquidity Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets					2.00%	[1]	2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation, weighted average	[1]		2.00%

[1] Allocations exclude consideration of a group annuity contract held by the LG&E and KU Retirement Plan.

[2] In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.

[3] Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.

[4] Includes commingled debt funds, which PPL treats as debt securities for asset allocation purposes.

[5] In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.

[6] Includes commingled debt funds.

[7] Includes money market funds.

[8] In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.

[9] Includes commingled debt funds and debt securities.

[10] Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.